Although various types of transmission systems have proven useful in construction machines and other industrial machines for performing tasks and conveying materials, the parallel path variator transmission has been widely adopted for its ability to provide a continuously variable output with a good degree of efficiency. In particular, the parallel path variator (PPV) transmission provides the power and range needed to allow necessary tasks to be performed while minimizing the cost of ownership and operation and ensuring that standards for performance and emissions can be met.
Within the class of PPV transmissions, the common design element is generally a two input system wherein a primary power source, e.g., an internal combustion engine, operates at a generally constant rotational speed to provide one transmission input, while a variable speed source provides the other input. The variable speed source may be an electric motor, hydraulic motor, and so on. The PPV transmission is configured to provide an output rotation speed and torque that is a function of the characteristics of the two inputs.
While PPV transmissions thus provide excellent operational characteristics, they do so at a cost in terms of space and complexity. For example, a typical PPV system is fairly large, incorporating numerous countershafts and peripheral components, which all contribute to the cost, complexity, and footprint of the system.
It will be appreciated that this background description has been created by the inventor to aid the reader, and is not to be taken as a reference to prior art nor as an indication that any of the indicated problems were themselves appreciated in the art.